Particularly throughout the Midwest, metal roofed buildings and buildings with metal joints have become very common from uses in agricultural and other industries. These buildings, while lightweight and inexpensive to build, do have certain problems from the standpoint of satisfactory weathering, especially in the severe weather extremes of the Midwest. Particularly, in a single year they are subjected to unusually hot temperatures, extreme cold temperatures, and high degrees of moisture. Such metal buildings are therefore susceptible to rusting and corrosion. The buildings are therefore in need of protective coatings on their surfaces, especially at the joints and on the roof.
In the past, joint sealing compositions and roof coverings for metal roofs have been of two particular types, namely, elastomeric latex systems and asphaltic systems. Latex systems have the disadvantage of very poor adhesion, and at the same time they require extensive and time consuming preparation in order for proper application. Because of the extensive time required for proper preparation for application, these steps are often skipped when using elastomeric latexes. As a result the latex is often placed on the metal without proper preparation, thus, increasing the risk of poor adhesion. As a result elastomeric latex compositions especially for roof and metal joint sealing have no been widely accepted.
The other type of system commonly used system is asphaltic emulsions. Asphalt, while less expensive, proves not to be thermally stable under the drastic weather extremes of the Midwest. Thus, it tends to crack in the winter time, and tends to become less viscous and run in the summertime. As a result, it too has significant deficiencies as an effective metal sealant and metal roofing composition.
Yet another problem exists with both asphaltic compositions and latex compositions. This is in regard to their use in treating currently existing metal coverings. That is to say, it often happens that existing roofing compositions and joint sealers, when they become cracked and weathered, need themselves to be covered over. Thus, a good composition is one which will not only adhere to metal, but which can be applied over existing, but unsatisfactory roofing and joint sealing compositions.
The rubberized roofing composition and rubberized seam compound of the composition of the present invention satisfy each of the above needs. In particular, the composition of the present invention has needed flexibility, tensile strength, and adhesion to withstand the expansion and contraction encountered at seams, joints, and penetrations. Also, the composition of the present invention has excellent adhesion to metals, including aluminum, galvanized steel, and painted surfaces, and at the same time, resists cracking and peeling. Compositions of the present invention are also compatible with reinforcing materials such as polyester mesh, can be easily applied using either a troll or a caulking style loader and, because of the coaction of the combination of four later listed critical ingredients, adequately perform in the severe weather extremes of the Midwest.
The composition which achieves all of the above advantages, as well as others, will become apparent from the detailed description of the invention which follows hereinafter.